High Electronic Conductivity Research Articles

High‐Performance MCNTs@MoS2(1‐x)Se2x Nanocomposites in Catalytic Hydrogen Evolution

AbstractAdvances in electrocatalysis require the development of high specific surface area materials with high electron conductivity. In this study, a series of MCNTs@MoS2(1‐x)Se2x nanocomposites has been prepared for application in catalytic hydrogen evolution. A uniform growth of MoS2(1‐x)Se2x nanoflower spheres on MCNTs has been achieved, circumventing stacking and aggregation. The introduction of the conducting material accelerated the electron transport rate in the electrode reaction. Structural characterization has confirmed that S doping increased the specific surface area of the catalyst, exposing more edge defects. As a result, the MCNTs@MoS2(1‐x)Se2x nanocomposites exhibited enhanced catalytic activity. Electrochemical tests have established that MCNTs@MoS1.5Se0.5 possessed the lowest overpotential (146 mV) at a current density of 10 mA/cm2 with the smallest Tafel slope (45.1 mV/dec).

Design of high-performance binary carbonate/hydroxide Ni-based supercapacitors for photo-storage systems

Silicon solar cells were used to convert solar energy into electrical energy, and a supercapacitor was designed to store this energy. To maximize the surface area of the electrodes, a three-dimensional Ni foam substrate was employed, onto which Ni-based compounds were deposited to enhance the electrochemical performance of the electrodes. Specifically, to address the conductivity reduction problem that arises when using only Ni ions, we introduced transition metal ions such as Mn, Co, Cu, Fe, and Zn to create binary compounds as electrode material. These binary metal compounds provided high electronic conductivity, structural stability, and reversible capacity, thereby optimizing the performance of the supercapacitor. As a result, the optimized NiCo(CO3)(OH)2 electrode demonstrated high capacity and excellent cycle stability, exhibiting an energy density of 35.5 Wh kg−1 and a power density of 2555.6 W kg−1 as an asymmetric supercapacitor device. Furthermore, when this device was combined directly with silicon solar cells, it achieved a storage efficiency of 63 % and an overall efficiency of 5.17 % under an illumination intensity of 10 mW cm−2. These findings suggest the potential for commercializing high-performance self-charging energy storage devices and contribute significantly to the advancement of energy storage technology.

Understanding Electrochemical Reaction Mechanisms of All-Electrochem-Active Mg2Si Electrode in All-Solid-State Batteries.

To better understand the electrochemical reaction mechanism of the Mg2Si electrode in all-solid-state batteries (ASSBs), a rational all-electrochem-active Mg2Si electrode is first designed to minimize the inactive component-related interfacial degradation. This is due to its unique mixed conductivity properties, including a high electronic conductivity of up to 8.9 × 10-2 S cm-1 and an ionic conductivity of 9.7 × 10-5 S cm-1, which allow for fast charges transport. In ASSBs, the Mg2Si electrode exhibits a higher initial Coulombic efficiency of 83.5% at 300 mA g-1 compared with the Si electrode (72.3%). X-ray diffraction and X-ray photoelectron spectroscopy results demonstrate that intermediate products (LixMg2Si, Li-Si alloy, and Li-Mg alloy) can form when the Mg2Si electrode discharges to 0.01 V, and partial Mg2Si still does not react with lithium. This work provides valuable insights into the reaction mechanisms and guides optimization strategies for developing next-generation Si-based ASSBs.

An Efficient Cathode Catalyst for Rechargeable Zinc-air Batteries based on the Derivatives of MXene@ZIFs.

Oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are crucial processes at the cathode of zinc-air batteries. Developing highly efficient and durable electrocatalysts at the air cathode is significant for the practical application of rechargeable zinc-air batteries. Herein, N-doped layered MX containing Co2P/Ni2P nanoparticles is synthesized by growing CoNi-ZIF on the surface and interlayers of the two-dimensional material MXene (Ti2C3) followed by phosphating calcination. The growth of CoNi-ZIF on the surface of MXene results in the attenuation of high-temperature structural damage of MXene, which in turn leads to the formation of Co2P/Ni2P@MX with a hierarchical configuration, higher electron conductivity, and abundant active sites. The optimized Co2P/Ni2P@MX achieves a half-wave potential of 0.85 V for the ORR and an overpotential of 345 mV for the OER. In addition, DFT calculations were adopted to investigate the mechanism at the atomic and molecular levels. The liquid zinc-air battery with Co2P/Ni2P@MX as the cathode exhibits a specific capacity of 783.7 mAh g-1 and exceeds 280 h (840 cycles) cycle stability, superior to zinc-air batteries constructed by the cathode of commercial Pt/C+RuO2 and other previous works. Furthermore, a solid-state battery synthesized with Co2P/Ni2P@MX as the cathode exhibits stable cycle performance (154 h/462 cycles).

High‐Performance Alkaline Battery‐Supercapacitor Hybrid Based on Bimetallic Phosphide/Phosphate

AbstractTransition metal‐based materials explored for energy storage applications viz. batteries, supercapacitors and more recently battery‐supercapacitor hybrids (BSHs) abundantly involve Co‐based materials. However, the supply chain issues and low electronic conductivity force us to look for alternative options. In this regard, Co‐free binary metal phosphide/phosphate consisting of Ni and V metal (NiVP/Pi) microspheres as the positive electrode of BSH which shows a high specific capacity of 502 C g−1 (1004 F g−1) at 2 mV s−1 while retaining a high specific capacity of 214 C g−1 (428 F g−1) at 12 A g−1 is reported. The high electronic conductivity of binary metal phosphide in NiVP/Pi electrode and the rich electrochemical active sites due to Ni and V metal centres results in exciting performance. More interestingly, the hybrid device is successfully developed by employing NiVP/Pi as the positive electrode and carbon nanotubes (CNTs) as the negative electrode. The hybrid device (NiVP/Pi//CNT) is able to achieve a maximum energy density of 22.17 Wh kg−1 and a power density of 5 kW kg−1 with 91.7% capacitance retention after 7500 continuous galvanostatic charge–discharge cycles.

Heterostructured GCN Nanosheets/ZnO nanoflowers for enhanced TMO loading: From high-performance three electrode systems to printed flexible asymmetric supercapacitors

Transition metal oxides (TMOs) are widely used in the development of high-energy-density devices due to their multiple oxidation states and their frequent heterostructuring with carbon-based materials. However, the synthesis process often leads to severe nanoparticle agglomeration and weak synergistic effects with carbon-based templates, thereby limiting their application potential. In this study, we constructed graphitic carbon nitride (GCN) nanosheets/ZnO nanoflowers (NFs) structures with high TMOs loading by utilizing GCN nanosheets, which are rich in surface nitrogen content, as enriched templates for metal ions in conjunction with ultrasonic cavitation. Compared with GCN nanosheets/ZnO nanoparticles (NPs), the ZnO NFs exhibited vertical growth and a fluffy structure on a 2D material template, which resulted in high electronic conductivity, a large effective surface area, hierarchical pores, and strong synergistic interactions with GCNs, thus improving electrochemical performance. This structural enhancement enabled the GCN/ZnO NFs electrodes to achieve a high specific capacitance of 1524F g−1 at a current density of 1 A g−1 in a three-electrode supercapacitor system. Additionally, we formulated GCN/ZnO NFs into electronic inks and used them for the mass production of flexible supercapacitors with the aid of dispensing printing technology. These flexible supercapacitors retained 94% of their specific capacitance even under extreme conditions of 90° torsion. Our proposed strategy of modulating TMOs and 2D structures can create active electrode materials with higher loading capacities, thereby enabling comprehensive customization in material design and device preparation processes.

Enhancing Li4Ti5O12 Anodes for High‐Performance Batteries: Ti3+ Induction via Plasma‐Enhanced Chemical Vapor Deposition and Dual Carbon/LLZO Coatings

AbstractLithium titanium oxide (LTO) is a promising anode material due to its ability to store lithium through intercalation reactions. However, its electrochemical performance is limited by poor electron conductivity and side reactions with the electrolyte. In this study, plasma‐enhanced chemical vapor deposition (PECVD) is employed to introduce oxygen vacancies and self‐doped Ti3+ into LTO to improve the internal conductivity. Subsequent carbon coating and aluminum‐doped lithium lanthanum zirconate garnet (LLZO) layers resulted in a multi‐layered composite denoted as LTO−L‐x. Morphological analyses using SEM and TEM demonstrated the successful growth of Al‐doped LLZO on carbon‐coated LTO. Aluminum ions in LLZO cubic structure are crucial for stabilizing the high ionic conductive phase during cooling, as confirmed by X‐ray diffraction. The dual coating layers have a significant impact on the rate capability, reducing polarization gaps and enabling higher capacities at various current rates. Long‐term cycling tests reveal the robustness of the composite, with LTO−L‐1.0 retaining 90.8 % capacity after 4000 cycles at 1.0 A g−1. This underscores the sustained high electronic and ionic conductivity facilitated by the dual coating layers. The study contributes to the design of advanced anode materials for lithium‐ion batteries, emphasizing the importance of tailored coating strategies to address conductivity and stability challenges.

A Review of Perovskite-based Lithium-Ion Battery Materials

Lithium-ion batteries (Li-ion batteries or LIBs) have garnered significant interest as a promising technology in the energy industry and electronic devices for the past few decades owing to their superior energy and power density profiles, small size, long cycle life, low self-discharge rate, no memory effect, long-lasting power properties, and environmental friendly. The ongoing advancement of electrode and electrolyte materials has contributed significantly to enhancing and spreading the application of lithium-ion battery technology. Among the non-precious metal-based materials, perovskites have emerged as attention over the last decade, holding a prominent position in materials and energy. Due to their unique physical and chemical properties, these materials have garnered particular interest for their potential application in electrochemical energy devices. Perovskite oxides have piqued the interest of researchers as potential catalysts in Li-O₂ batteries due to their remarkable electrochemical stability, high electronic and ionic conductivity, and the ability to modify their properties through doping and element substitution. The purpose of this article is to provide an overview of recent developments in the application of perovskites as lithium-ion battery materials, including the exploration of novel compositions and structures, optimization of fabrication methods, and a deeper understanding of the fundamental mechanisms that can unveil the potential of perovskite materials.

Design Lithium Exchanged Zeolite Based Multifunctional Electrode Additive for Ultra‐High Loading Electrode Toward High Energy Density Lithium Metal Battery

AbstractThe practicalization of a high energy density battery requires the electrode to achieve decent performance under ultra‐high active material loading. However, as the electrode thickness increases, there is a notable restriction in ionic transport in the electrodes, limiting the diffusion kinetics of Li+ and the utilization rate of active substances. In this study, lithium‐ion‐exchanged zeolite X (Li‐X zeolite) is synthesized via Li+ exchange strategy to enhance Li+ diffusion kinetics. When incorporated Li–X zeolite into the ultra‐high loading cathodes, it possesses i) high electron conductivity with a uniform network by reducing tortuosity, ii) decent ion conductivity attributes to modulated Li+ diffusivity of Li‐X and iii) high elasticity to prevent particle‐level cracking and electrode‐level disintegration. Moreover, Li–X zeolite at the solid/liquid interface facilitates the formation of a stable cathode electrolyte interface, which effectively suppresses side reactions and mitigates the dissolution of transition cations. Therefore, an ultra‐high loading (66 mg cm−2) cathode is fabricated via dry electrode technology, demonstrating a remarkable areal capacity of 12.7 mAh cm−2 and a high energy density of 464 Wh kg−1 in a lithium metal battery. The well‐designed electrode structure with multifunctional Li–X zeolite as an additive in thick cathodes holds promise to enhance the battery's rate capability, cycling stability, and overall energy density.

Functional organic 7,7,8,8‐tetracyanoquinodimethane artificial layers for the dendrite suppressed lithium metal anodes

AbstractThe large‐scale industrialization of lithium metal (Li), as a potential anode for a high energy density energy storage system, has been hindered by dendrite growth. The construction of an artificial solid electrolyte interphase layer featuring high ionic and low electronic conductivity has been verified to be a high‐performance strategy to confine the dendrite growth and promote the Li anode stability. Therefore, a functional organic protective layer is homogeneously deposited on the Li anode surface via an in situ chemical reaction between tetracyanoquinodimethane (TCNQ) and Li. The as‐synthesized Lin‐TCNQ organic film could efficiently trap non‐uniform Li deposition and restrain dendrite propagation. Particularly, an asymmetric M‐TCNQ‐Li|Cu cell with the Lin‐TCNQ layer breezed through a high Coulombic efficiency of 91.15% after 100 cycles at 1.0 mA cm−2. The M‐TCNQ‐Li|NCM622 cell delivered a high capacity of 143.40 mAh g−1 at 0.2 C and maintained a good cyclic stability of 110.44 mAh g−1 after 160 cycles. The analysis results of spectroscopic tests further demonstrate that the Lin‐TCNQ with the enhanced absorption energy is conducive to lithiophilicity and decreases the overpotential of Li deposition.

3D Tunnel Copper Tetrathiovanadate Nanocube Cathode Achieving Ultrafast Magnesium Storage Reactions through a Charge Delocalization and Displacement Mechanism.

Rechargeable magnesium batteries are attractive candidates for large-scale energy storage applications because of the low cost and high safety, but the scarcity and inferior performance of the cathode materials are hindering the development. In the present study, a kind of copper tetrathiovanadate (Cu3VS4) cathode is designed and developed with a comprehensive consideration of the chemical and electronic structures. The vanadium and sulfur atoms form chemical bonds with high covalent proportion, facilitating electron delocalization via the vanadium-sulfur bonds. This reduces the interaction with the bivalent magnesium cation and induces the coredox of vanadium and sulfur. The crystal structure of Cu3VS4 has interlaced 3D tunnels for solid-state magnesium cation transport. The Cu3VS4 cathode shows a high capacity of 350 mA h g-1 at 100 mA g-1, an outstanding rate performance of 67 mA h g-1 at 10 A g-1, and stable cycling for 1000 cycles at 5 A g-1 without obvious capacity fading. Prominently, a high areal mass load of 3.5 mg cm-2 could be achieved without obvious rate capability decay, which is quite favorable to pair with the high-capacity magnesium metal anode in practical application. The mechanism investigation and theoretical computation demonstrate that Cu3VS4 undergoes first a magnesium intercalation and then a displacement reaction, during which the crystal structure is maintained, assisting the reaction reversibility and cycling stability. All the copper, vanadium, and sulfur elements experience redox and contribute to the high capacity. Moreover, the weakened interaction with magnesium cations, well-kept 3D cation transport tunnels, and high electronic conductivity result in the superior rate performance and high areal active material loading. The present study develops a high-performance cathode for rechargeable magnesium batteries and reveal the design principle based on both of chemical and electronic structures.

Impact Deposition of a Single Droplet of Low-Melting-Point Alloy as the Top Electrode for Organic Photovoltaics.

Top electrodes of organic photovoltaics (OPVs) are usually thermally evaporated in the vacuum, which is non-continuous and time-consuming and has been the bottleneck for the OPV fabrication process. Printable top electrodes that are free of vacuum, high temperature, and solvents will make OPVs more attractive. Low-melting-point alloys (LMPAs) are promising candidates for printable OPV electrodes thanks to the merits of matching work functions, high electron conductivity, high environment stability, and no need for post-treatment. Here, LMPA electrodes are directly deposited on OPVs by simply falling a single LMPA droplet onto the substrate. The LMPA droplet spreads to form a thin film with a smooth interface intimately contacting the substrate. The electrode area can be tailored by adjusting the droplet diameter or the Weber number, which is the ratio of inertia to surface tension. The interface morphology is mainly affected by the contact temperature. The degree of oxidation and charges on the droplet can also influence the electrode area and interface morphology. OPVs with droplet-impacted LMPA electrodes exhibit power conversion efficiencies of up to 16.17%. This work demonstrates the potential of single-droplet impact deposition as a simple method for printing OPV electrodes for scalable manufacturing.

Core-shell structure and high rate performance of Ce-doped Li4Ti5O12 for lithium-ion battery anode materials

Lithium titanate (LTO) can be a very promising anode material for lithium-ion batteries (LSBs) due to its inherent ability to inhibit the growth of lithium dendrites as well as its unique “zero-strain” properties. Unfortunately, the low electronic conductivity of LTO leads to serious shortcomings in higher electrochemical demands. In this work, the Ce3+-doped C@Li4Ti5-xCexO12 (x = 0, 0.1, 0.15 and 0.2) anode materials synthesized by the hydrothermal method using carbon spheres as templates showed more significant improvement in both structural and electrochemical properties. The results demonstrate that electronic conductivity, lithium-ion diffusion rate, discharge specific capacity, discharge rate capability, and significant improvement stability of C@Li4Ti5-xCexO12 (x = 0.1, 0.15 and 0.2) electrodes. Among them, C@Li4Ti4.85Ce0.15O12 electrode exhibits the highest initial discharge specific capacity (250.86 mAh/g) at 0.1C, which is 1.28-fold that of C@ Li4Ti5O12 (195.94 mAh/g), and initial discharge capacity from 205.96 mAh/g to 170.39 mAh/g after 500 cycles, corresponding to 82.7 % of the initial stable discharge capacity. The outstanding performance of C@Li4Ti4.85Ce0.15O12 can be attributed to the lower interfacial impedance, higher electronic conductivity, high oxygen vacancy concentration, and moderate amount of Ce3+ doping can enhance the electrochemical activity. In addition, carbon sphere surface defects shown to be effective in improving lithium-ion storage. This work demonstrates that Ce3+ doping is an effective method to improve the electrochemical performance of LTOs and provides a more effective guide for designing and optimizing anode electrode materials for lithium-ion batteries

Z-scheme heterostructures confining rGO/protonated C3N5 junction supported CoCu LDH positive electrode and Fe3O4 negative electrode for supercapacitors

CoCu LDH stabilized reduced graphene oxide-linked N-rich protonated C3N5 (CoxCuy@rGO/P-CN) as a power source Z-scheme nanocomposite was rationally tailored engineered an electrodeposition approach. The electrochemical performance was regulated by adjusting the electrodeposition potential and manipulating the Co/Cu molar ratio. Hence, affording compelling evidence for fine-tuning the performance of pseudo-active compounds. Benefiting from abundant heterointerfaces and synergistic effects between LDH nanoarrays and rGO/P-CN heterojunction, the hierarchical ‒1.2V Co3Cu1@rGO/P-CN Z-scheme positive electrode achieves a higher capacitance of 1184 F g–1 at 1 A g–1 and good rate capability performance. Theoretical simulation outcomes illustrate that the Co3Cu1@rGO/P-CN nanocomposite has higher electronic conductivity and superior electronic transition capability, originating from robust interactions between valence and conduction bands, interfacial charge transfer, and built-in electric field at the LDH/rGO/P-CN interface. We also explore the Fe3O4@rGO/P-CN Z-scheme as a negative electrode material via a simple annealing process with a capacitance of 402 F g–1 at 1 A g–1 and an enhanced cyclic performance. Consequently, the as-assembled ‒1.2V Co3Cu1@rGO/P-CN//Fe3O4@rGO/P-CN asymmetric supercapacitor (ASC) cell acquires a remarkable energy density of 63.4 Wh kg–1 at 750 W kg–1 and displays an exceptional cycling activity with 88% retention after 11,000 cycles.

Ultrasmall Fe‐Nanoclusters‐Anchored Carbon Polyhedrons Interconnected with Carbon Nanotubes for High‐Performance Zinc‐Air Batteries

The catalytic activity of metal catalyst is closely related to its particle size. Yet, the size effect in electrocatalytic oxygen reduction reaction (ORR), an important reaction for metal‐air batteries and fuel cells, has not been clearly studied. Herein, a two‐step anchoring method is utilized to control the Fe catalyst in forms of nanoparticles (NPs), ultrasmall nanoclusters (NCTs), and isolated atoms as well as stabilized and dispersed by carbon polyhedrons interconnected with carbon nanotubes (CNTs). The uniformly distributed Fe NCTs displays superior ORR performance compared with Fe NPs, isolated Fe atoms, and commercial Pt/C. The brilliant ORR activity of Fe NCTs is a result of its unique electron structure and abundant edge and corner active sites. Due to the porous structure of carbon polyhedrons and high electron conductivity of CNTs, Fe NCTs also delivers an excellent discharge performance in zinc‐air battery with a peak power density of 213.3 mW cm−2 and long‐term stability. In these findings, a new strategy for the design of metal NCTs catalysts applied in various catalytic reactions is opened up.

High‐Capacity, Long‐Life All‐Solid‐State Lithium–Selenium Batteries Enabled by Lithium Iodide Active Additive

AbstractSelenium (Se) shows promise as a cathode candidate for all‐solid‐state lithium (Li) batteries due to its impressive theoretical volumetric energy density, much higher electronic conductivity, and improved safety in comparison to those for sulfur (S). An active cathode additive, lithium iodide (LiI) is demonstrated, to address the major challenge for all‐solid‐state Li–Se batteries, namely the sluggish redox kinetics resulting from the huge solid‐state conversion barrier. The LiI additive enhances Li+ transport and provides catalytic sites for Se cathode, thus endowing the batteries with accelerated reaction kinetics and extra capacity. DFT calculation and experimental analysis clearly reveal that LiI additive efficiently accelerates the conversion between polyselenide intermediates and Li2Se. With the above advantages, the battery with LiI using Li6PS5Br electrolyte gives an outstanding capacity of 862 mAh gSe−1 beyond the theoretical specific capacity of Se and a superlong life over 1800 cycles at 1C under room temperature. This work offers a simple strategy to facilitate the kinetics of all‐solid‐state Se cathodes and paves the way for the practicality of high‐capacity and long‐life all‐solid‐state Li–Se batteries.

Dual optimization of LiFePO4 cathode performance using manganese substitution and a hybrid lithiated Nafion-modified PEDOT:PSS coating layer for lithium-ion batteries

The energy storage market necessitates an increase in the specific capacity of battery materials, particularly cathodes, to meet growing demands. Manganese (Mn) substitution of lithium iron phosphate (LFP) cathodes presents a promising avenue, offering high specific capacity and operability at elevated voltages. However, during cycling, the dissolution of Fe/Mn ions into the electrolyte leads to capacity fading. In this study, we enhance the specific capacity of LFP by Mn substitution in the iron position at various ratios (0.1, 0.2, 0.3, and 0.4). LiFe0.6Mn0.4PO4 exhibits the highest capacity of 159.1 mAh g-1 at 0.1C with an initial Coulombic efficiency of 97.9 %. This improvement stems from an enhanced lithium diffusion coefficient, increasing from 1.86 × 10–14 cm2 s-1 for pristine LFP to 2.46 × 10–12 cm2 s-1 for LiFe0.6Mn0.4PO4. However, LiFe0.6Mn0.4PO4 demonstrates the poorest capacity retention among the substituted samples, reaching 78.4 % over 100 cycles due to severe Fe/Mn ion dissolution. To address this issue, we coat Mn-substituted LFP with poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) and lithiated Nafion (LN) polymer, which offer high electronic and lithium-ion conductivity, respectively. This coating layer enhances the capacity retention of LiFe0.6Mn0.4PO4 to 90.1 % at 0.2C after 100 cycles, effectively mitigating active material loss during charge-discharge processes. This study demonstrates that PEDOT:PSS-LN can improve the electronic and ionic conductivity of cathode materials and maintain high capacity retention during cycling.

3D structured lithiophilic current collector with lithiation nucleation overpotential near 0 V for dendrite-free lithium metal anode

The poor lithium affinity of most metal skeletons leads to uneven electric field distribution, resulting in the notorious Li dendrite growth. Herein, a 3D structured Cu mesh@Ag current collector is introduced using a simple chemical plating method to enable dendrite-free Li anode. The high electronic conductivity and matrix pore structure of Cu mesh can alleviate the local current density and provide buffer space for lithium deposition. The lithiophilic Ag can form infinite solid solution with Li while reducing the initial lithiation nucleation overpotential to about 0 V, achieving homogenous Li deposition. As a result, the symmetric cell can maintain a low polarization voltage (20 mV) after cycling at 0.5 mA cm-2 for 1300 h Full cells assembled with LiFePO4 cathode present a long-term cycling stability of 500 cycles at 1C with a capacity retention of 80.3%. This work provides a reliable approach to create stable Li-metal batteries.

Ultrahigh Pyridinic/Pyrrolic N Enabling N/S Co-Doped Holey Graphene with Accelerated Kinetics for Alkali-Ion Batteries.

Carbonaceous materials hold great promise for K-ion batteries due to their low cost, adjustable interlayer spacing, and high electronic conductivity. Nevertheless, the narrow interlayer spacing significantly restricts their potassium storage ability. Herein, hierarchical N, S co-doped exfoliated holey graphene (NSEHG) with ultrahigh pyridinic/pyrrolic N (90.6at.%) and large interlayer spacing (0.423nm) is prepared through micro-explosion assisted thermal exfoliation of graphene oxide (GO). The underlying mechanism of the micro-explosive exfoliation of GO is revealed. The NSEHG electrode delivers a remarkable reversible capacity (621 mAhg-1 at 0.05 Ag-1), outstanding rate capability (155 mAhg-1 at 10 Ag-1), and robust cyclic stability (0.005% decay per cycle after 4400 cycles at 5 Ag-1), exceeding most of the previously reported graphene anodes in K-ion batteries. In addition, the NSEHG electrode exhibits encouraging performances as anodes for Li-/Na-ion batteries. Furthermore, the assembled activated carbon||NSEHG potassium-ion hybrid capacitor can deliver an impressive energy density of 141 Whkg-1 and stable cycling performance with 96.1% capacitance retention after 4000 cycles at 1 Ag-1. This work can offer helpful fundamental insights into design and scalable fabrication of high-performance graphene anodes for alkali metal ion batteries.

Enhancing micro-scale SiOx anode durability: Electro-mechanical strengthening of binder networks via anchoring carbon nanotubes with carboxymethyl cellulose

With the increasing prevalence of lithium-ion batteries (LIBs) applications, the demand for high-capacity next-generation materials has also increased. SiOx is currently considered a promising anode material due to its exceptionally high capacity for LIBs. However, the significant volumetric changes of SiOx during cycling and its initial Coulombic efficiency (ICE) complicate its use, whether alone or in combination with graphite materials. In this study, a three-dimensional conductive binder network with high electronic conductivity and robust elasticity for graphite/SiOx blended anodes was proposed by chemically anchoring carbon nanotubes and carboxymethyl cellulose binders using tannic acid as a chemical cross-linker. In addition, a dehydrogenation-based prelithiation strategy employing lithium hydride was utilized to enhance the ICE of SiOx. The combination of these two strategies increased the CE of SiOx from 74% to 87% and effectively mitigated its volume expansion in the graphite/SiOx blended electrode, resulting in an efficient electron-conductive binder network. This led to a remarkable capacity retention of 94% after 30 cycles, even under challenging conditions, with a high capacity of 550 mA h g−1 and a current density of 4 mA cm−2. Furthermore, to validate the feasibility of utilizing prelithiated SiOx anode materials and the conductive binder network in LIBs, a full cell incorporating these materials and a single-crystalline Ni-rich cathode was used. This cell demonstrated a ∼27.3% increase in discharge capacity of the first cycle (∼185.7 mA h g−1) and exhibited a cycling stability of 300 cycles. Thus, this study reports a simple, feasible, and insightful method for designing high-performance LIB electrodes.